Automatic time switch



March 22, 1932. SHERMAN 1,850,421

AUTOMATIC TIME SWITCH Filed Sept. 13, 1926 Patented Mar. V22, 1932 JOHN Q. SHERMAN, F DAY'EGN, @HIQ AUTOMATIC Tmhl SWI'EGE Application filed September 13, 1956. Serial ito. 135,1

My invention relates to time switches for automatically opening electric circuits and the like.

It frequently occurs that electrically operated devices such as pressing irons in tailoring and dressmaking establishments, sewing machines, various motor driven mechanism in factory operation and domestic electrical appliances are used for only short to periods of time and the operator some times forgets or neglects to turn oil the current when the operation is completed. This results in a great waste of electrical current and unnecessary expense of operation and moreover greatly increases danger from fires and results in deterioration and injury of the electrically operated devices.

In the present invention there is contemplated a time operated switch mechanism 2 1 which may be incorporated in the. electrical device or appliance or may be utilized as a plug or attachment connected with an electrical supply outlet to which various devices or electrical apparatus may be connected.

5 The present disclosure embodies a manually operated switch lever which by its depression serves to close the electrical switch contacts against the pressure of a retractive spring. These contacts are held in closed position by a spring actuated detent. The movement of the switch lever necessary to close the contact also serves to wind or tension the actuating spring of a clockwork mechanism. This clockwork mechanism actuates a rotary timing cam or .disc having thereon at spaced intervals cam projections which serve to release the switch contact after a predetermined period of current supply. At each operation of the lever necessary to reconnect the contacts, the throwout or disengaging device is advanced automatically from its operated position to permit the return of the electrical contacts into engagement with each other.

5 The object of invention is to simplify the operation of such automatic electrical switches whereby they will not only be cheapened in construction but will be more elfi- 0 cient in use, positive'in operation, uniform structure as well as the means and mode of,

in action and unlikely to get out of repairs.

A further object of invention is to provide improved means for automatically disconnecting an electric current supply after a predetermined period of operation.

A further object of invention is to provide improved timing means by which the switch parts will be released after the lapse of a preetermined time period and to further proyide means for winding or resetting the timmg mechanism at time of the reengagement of the switch contacts.

With the above primary and other incidem tal objects in view as will more fully appear inthe specifications the invention consists of the features of construction the parts and combinations thereof and their mode oi operation or their equivalents, as hereinafter de scribed and set forth in the claims.

Referring to the accompanying drawin s 79 wherein is shown the preferred but obvious y not necessarily the only form of embodiment 'nvention Figs. 1 and 2 are side elevations or of the assembled time controlled switch mechanism viewed at right angles to each other, the enclosing casing or housing broken away to expose the operating parts therein. Figs. 3 and i are enlarged detail views of the contact operating parts viewed at right angles to each other. 39

Like parts are indicated by similar charac- I ters of reference throughout the several views.

In the drawings 1 is a housing or casing enclosing the operating part of the switch 8 mechanism. This housing may be connected 3 directly to a socket or outlet and is provided with a. cap 2 through which a conductor cord extends into connection with the switch mechanism or the present switch device may be directly connected with an electrical mechanism or appliance. Located within the housing 1 is a flexible switch contact arm 3 connected with one of the terminals 2. This contact arm 3 co-acts with a corresponding contact 4, carried by a depressible switch arm 5. The switch arm 5 is pivoted at 6 within a the housing 1 and projects there beyond carrying at its outer end a button 7 for manual engagement by the operator. The contact element 4 is provided with a body portion 8' by which it is connected to the operating lever 5. The body portion 8 is provided with parallel peripheral grooves 9 and 10. A spring v ment 4 in either its depressed or elevated position. Upon depressionof the switch lever 5 against the yielding resistance of its retractin}; spring 5' the contact 4 engages with the contact arm 3 and is held in such position by the detent 11 engaging in the groove 10. Upon the upper movement of the contact 4 out of engagement with the contact 3 due to the engagment of a cam projection upon the control disc with the lower end of the body portion 8 as hereafter described, the detent 11 will pass from the groove 10 to the groove 9 and so hold the contact 4 and operating lever 5 in their elevated or inoperative position.

Located within the housing 1 in position to engage with the lower end of the body por- -tion 8 of the contact member4 is a revoluble timingdisc 12 actuated by clockwork mechanism conventionally indicated at 13. The disk 12 is operatively connected with the clock work mechanism through a suitable frictional drive clutch (not shown) which enables independent relative adjustment of the disk as hereinafter described. The timing disc 12 is provided at spaced intervals,

with cam projections 14 which as the cam rotates successively engages with the lower end of the member 8 to elevate such member and with it the contact-4 and operating lever 5' against the yielding resistance of the spring actuated detent 11. J A winding stem 15 is provided for winding or tensioning the clockwork mechanism 13. In addition to this means for winding the clockwork mechanism manually, means is provided for automatically winding or tensioning the clockwork mechanism at each operation of the switch. To this end a dependent reciprocatory rack bar 16 is connected to the outer end of the actuating lever 5. This rack bar 16 engages a gear pinion 17 upon the winding stem 15 of the clockwork mechanism.

. The gear pinion 17 is loosely journaled upon the winding stem 15 and is operatively engaged therewith by a friction clutch connection under the influence of the spring 18 surrounding the winding stem 15. Thus at each depression of the control lever 5 the rack bar 16 is given longitudinal movement suflicient to afford rotation of the gear pinion 17 which is transmitted through the frictional engagement to the winding stem 15. Such friction clutch 1 connection, however, enables the independent manual winding operation of the stem 15, and prevents overwinding.

In the event that the device is connected to an electrical outlet terminal overhead, a cord or chain 20 may be attached to the lower end of the reciprocatory rack bar 16, for

manual operation of the bar and with it the lever 5 and contact member 4. The contact 4 is held in depressed position and in engagement with the contact 3 by the engage ment of the spring detent 11 in the groove 10. Any one of thecam projections 14 upon the disc 12 engaging the lower end of the member 8 as the disc 12 rotates will press such member upwardly to break the engagement of the contacts 3 tad 4. The detent 11 by its engagement in the groove 9 will then retain the parts in disengaged or elevated position. To insure the removal of the cam projection 14 out of the path of the member 8 preparatory to the next reengaging opera-a tion a pawl arm 21 is carried by the lever 5 and is adapted to engage a shoulder 22 onthe periphery of the disc 12 upon depression of the lever .5 to give to such disc sufficient advance movement to displace the cam projection 14 out of interference with the member 8 during its descending movement. The cam disc 12 is preferably pro vided with a peripheral groove 23 in which the end of the pawl 21 will ride.

There is one ratchet shoulder 22 for each of the cam projections 14. These ratchet shoulders are preferably formed within the erator need pay no attention to cutting off the currentwhen the operation of the connected appliance has been completed. At regular intervals depending upon the relative spacing of the cam projections 14 upon the disc ,12 one of such cam projections will pass the member 8 which in, its depressed position extends into the path of such cam projection. The interengagement of the cam projection 14 with the member 8 will elevate the latter thereby opening the circuit by disconnecting the contacts 3 and 4. The cam projections 14- may be so spaced and the disc 12 driven at such rate that the switch mechanism will be automatically operated to open the circuit at various predetermined intervals of time. The pawl arm 21 is held in engagement with the disc 12 at all times by a spring 24,1preparatory to advancing thedisc to move t e cam projection 14 out of the path of the member 8 when it is desired particular features of advantage before enumerated as desirable, but which obviously is susceptible of modification in its form, proportions, detail construction and arrange ment of parts without .departing from the principle involved or sacrificing any of its advantages.

While in order to comply with the statute the invention has been described in language more or less specific as tostructural features, it is to be understood that the invention is not limited to the specific details shown, but that the means and construction herein disclosed comprises the preferred form of several modes of putting the invention into effect and the invention is, therefore, claimed in any of its forms or modifications within the legitimate and valid scope of the appended claims.

Having thus described my inventlon, I claim:

1. In a time switch for electrical circults, a movable make and break contact member, manually operated means for moving the contact member to closed position, means for yieldingly holding the contact in either open or closed position, a revoluble cam member, means for actuating the cam, means movable with the contact member and extending into the path of the cam when the contact is in its closed position and engaged by the cam to move the contact from its closed to its open position by the further movement of the cam, and means for energizing the cam actuating means by the manual operation of the contact from its open to its closed position.

2. In a time switch for electrical circuits, a make and break switch contact, aI stem therefor having spaced recesses, a detent yieldingly engaging in said recesses alternately to hold the contact in open and closed position accordingly, manual means for moving the contact into closed position, timing means and means controlled thereby to automatically move the contact from closed to open position.

3. In a time switch for electrical circuits, a make and break switch contact, a detent yieldingly maintaining the contact in either open or closed position, manual means for moving the contact from open to closed position, time controlled actuating mechanism, a rotary cam disc actuated thereby, means extending into the path of movement of the cam disc when the contact is in closed position, and engaged thereby to automatically move'the contact from closed to open position at the end of a predetermined period of elapsed time.

, 4, In a time switch for electrical circuits, a make and break switch, for yieldingly holding the switch in open and closed positions, manually operated means for closing the switch, a time controlled actuating mechanism, means actuated thereby for automatically opening the switch at predetermined time intervals, and means for actuating the automatic switch operating means through an advance step independent of the time controlled mechanism by the manual operation of closing the switch.

5. In a time switch for electrical circuits, a make and break switch, a manually operated actuator for closing the switch, a clockwork timing mechanism, means actuated thereby for opening the switch automatically after an elapsed period of time, a winding stem for the clock work mechanism, a gear pinion on said stem, clutch means operatively connecting the pinion with the stem for driving the stem by rotation of the pinion but permitting independent rotation of the stem, a gear element meshing with said pinion and operated by the manual closing of the switch to rotate the pinion to rewind the clock work mechanism, said clock work mechanism being capable of being rewound independent of the closing operation of the switch by the rotation of the stem independent of said pinion.

6. In a time switch for electrical circuits, a make and break switch, a manually operated actuator for closing the switch, a clockwork timing mechanism, means actuated thereby for opening the switch automatically after an elapsed period of time, and means for giving to said switch opening means an initial advance step independent of the clock Work mechanism upon the closing of the switch.

7. In a time switch for electrical circuits, a make and break switch, a manually operated actuator for closing the switch, a clockwork timing mechanism, means actuated thereby JOHN o. SHERMAN. 

